The prior art is documented with examples of speed loader devices for use with a cylindrical barrel such as a revolver style pistol or other firearm and for quickly loading a plurality of cartridges into the barrel when rotated to the open position.
McClellan, U.S. Pat. No. 7,363,845, teaches a concealable speed loader for firearms including a flexible, one-piece body having a flat open condition defined by a plurality of living hinges configured in crosswise, plural and spaced apart fashion and, when joined end to end, defining a closed annular condition with two ends and a given width. The body has grasping chambers for receiving cartridges with a length substantially greater than the given width, causing part of the length of the cartridges to protrude from the body in both the open and the closed conditions. A locking latch latches the two ends of the body in the closed condition for placement above a cylinder of a firearm with the cartridges protruding into chambers of the cylinder. The locking latch has a knob to be pulled for manually removing the body and releasing the cartridges in turn as the cylinder rotates and the cartridges drop fully into the chambers of the cylinder.
Other references drawn from the prior art include the loading device for revolvers of Matich, U.S. Pat. No. 3,213,559 which teaches an apparatus for loading cartridges into the cylinder of a revolver. The apparatus includes an elongated flexible belt having a plurality of longitudinally spaced transverse divider walls extending from one side of the belt, the intermediate portion of each wall being concave on opposite faces to format the end of each wall farthest from the belt for holding cartridges in an arrangement to fit into the revolver cylinder, the belt, walls, and abutting adjacent ribs combining to extend around substantially the entire circumference of each cartridge to secure each cartridge along a substantial portion of its length within its respective recess.
Yet additional references of note include the cartridge loader for revolvers of U.S. Pat. No. 4,325,198 to Muck et al., the snap link type cartridge speed loading device of Billman, U.S. Pat. No. 4,614,053, and the link type cartridge speed loading device of Goyanes U.S. Pat. No. 4,862,622.